The present invention relates to integrated optical devices generally and more particularly to packaging of integrated optical devices.
Various types of integrated optical devices are known. It is well known to pigtail an optical fiber onto an integrated optical device. Difficulties arise, however, when it is sought to pigtail multiple optical fibers onto integrated optical devices. When the optical modes in waveguides and optical fibers are similar, it is conventional to pigtail them by suitable alignment and butt coupling in an integrated optical device.
When there exists a substantial disparity in the respective optical modes of the optical fibers and the waveguides, optical elements must be employed to enable successful pigtailing. Particularly when the optical modes are relatively small, very high alignment accuracy is required in the alignment of three elements, the waveguide, the optical element and the fiber.
The following patents are believed to representative of the present state of the art: U.S. Pat. Nos. 5,737,138; 5,732,181; 5,732,173; 5,721,797; 5,712,940; 5,712,937; 5,703,973; 5,703,980; 5,708,741; 5,706,378; 5,611,014; 5,600,745; 5,600,741; 5,579,424; 5,570,442; 5,559,915; 5,907,649; 5,898,806; 5,892,857; 5,881,190; 5,875,274; 5,867,619; 5,859,945; 5,854,868; 5,854,867; 5,828,800; 5,793,914; 5,784,509; 5,835,659; 5,656,120; 5,482,585; 5,482,585; 5,625,726; 5,210,800; and 5,195,154.
The present invention seeks to provide a cost-effective and reliable integrated optics packaging technique and optical devices constructed thereby.
There is thus provided in accordance with a preferred embodiment of the present invention an optical device including at least one first substrate defining a multiplicity of optical fiber positioning grooves, a multiplicity of optical fibers fixed in each of the multiplicity of optical fiber positioning grooves on the at least one first substrate, whereby the multiplicity of optical fibers lie in an optical fiber plane and the ends of each of the multiplicity of optical fibers lie substantially in a first predetermined arrangement in the optical fiber plane, a second substrate fixed onto the at least one first substrate such that an edge of the second substrate extends beyond the ends of each of the multiplicity of optical fibers, a lens assembly including a third substrate, and a lens fixed onto the third substrate, the lens assembly being mounted onto the second substrate such that the lens lies in a second predetermined arrangement with respect to the ends of each of the multiplicity of optical fibers, whereby the separation between the lens and the ends of each of the multiplicity of optical fibers is defined in a plane perpendicular to the optical fiber plane to a first degree of accuracy and the separation between the lens and the ends of each of the multiplicity of optical fibers is defined in the optical fiber plane to a second degree of accuracy, less than the first degree of accuracy.
Further in accordance with a preferred embodiment of the present invention the at least one first substrate comprises a pair of first substrates having the optical fiber positioning grooves thereon arranged in mutually facing relationship.
Still further in accordance with a preferred embodiment of the present invention the lens comprises a cylindrical lens which extends along a cylindrical lens axis. Preferably the cylindrical lens axis lies parallel to the optical fiber plane.
Additionally in accordance with a preferred embodiment of the present invention the third substrate is fixed in engagement with the edge of the second substrate by an adhesive. Preferably the third substrate is fixed in engagement with the edge of the second substrate by an adhesive.
Additionally in accordance with a preferred embodiment of the present invention the multiplicity of optical fiber positioning grooves are mutually parallel. Preferably the multiplicity of optical fiber positioning grooves are arranged in a fan arrangement in order to compensate for optical aberrations.
There is also provided in accordance with a preferred embodiment of the present invention a method for producing an optical device including the steps of forming a multiplicity of optical fiber positioning grooves on at least one first substrate, placing each of a multiplicity of optical fibers in each of the multiplicity of optical fiber positioning grooves on the at least one first substrate, retaining each of the multiplicity of optical fibers in each of the multiplicity of optical fiber positioning grooves on the at least one first substrate, such that the multiplicity of optical fibers lie in an optical fiber plane, precisely defining the ends of each of the multiplicity of optical fibers so that they all lie substantially in a first predetermined arrangement, fixing a second substrate onto the at least one first substrate such that an edge of the second substrate extends beyond the ends of each of the multiplicity of optical fibers, fixing a lens onto a third substrate, precisely aligning the third substrate in engagement with the edge of the second substrate such that the lens lies in a second predetermined arrangement with respect to the ends of each of the multiplicity of optical fibers, and fixing the third substrate in engagement with said edge of the second substrate such that the lens lies in a second predetermined arrangement with respect to the ends of each of the multiplicity of optical fibers, whereby the separation between the lens and the ends of each of the multiplicity of optical fibers is defined in a plane perpendicular to the optical fiber plane to a first degree of accuracy and the separation between the lens and the ends of each of the multiplicity of optical fibers is defined in the optical fiber plane to a second degree of accuracy, less than the first degree of accuracy. Preferably the step of fixing the third substrate in engagement with the edge employs an adhesive and the step of precisely aligning the third substrate in engagement with the edge of the second substrate employs an external positioner.
Further in accordance with a preferred embodiment of the present invention the at least one first substrate includes a pair of first substrates having the optical fiber positioning grooves thereon arranged in mutually facing relationship.
Additionally or alternatively the lens includes a cylindrical lens which extends along a cylindrical lens axis. Preferably the precisely aligning step and the fixing step arrange the cylindrical lens such that the cylindrical lens axis lies parallel to the optical fiber plane.
Preferably the multiplicity of optical fiber positioning grooves are mutually parallel.
Alternatively accordance with a preferred embodiment of the present invention the multiplicity of optical fiber positioning grooves are arranged in a fan arrangement in order to compensate for optical aberrations.
There is further provided in accordance with a preferred embodiment of the present invention an optical device including at least one optical substrate having formed thereon at least one waveguide, at least one base substrate onto which the at least one optical substrate is fixed, and at least one optical module, precisely positioned onto each at least one base substrate and fixed thereto by means of side mounting blocks thereby to preserve precise mutual alignment of the at least one module and the at least one waveguide.
Further in accordance with a preferred embodiment of the present invention the at least one optical module includes a lens or includes a cylindrical lens, and at least one optical fiber.
Preferably the at least one optical module also includes a lens which is operative to couple light from the at least one fiber to the at least one waveguide and also including the step of positioning output optics including at least one output fiber on the at least one base substrate so as to receive light from the at least one waveguide. Additionally or alternatively the lens is operative to couple light from a first number of fibers to a greater number of waveguides.
Additionally in accordance with a preferred embodiment of the present invention the at least one waveguide includes stacking a plurality of base substrates each having mounted thereon at least one optical substrate having formed thereon at least one waveguide and wherein the step of positioning the output optics includes arranging at least one lens to receive light from waveguides formed on multiple ones of the plurality of optical substrates. Preferably the step of positioning the output optics includes employing side mounting blocks thereby to preserve precise mutual alignment of said at least one lens and the at least one waveguide.
Still further in accordance with a preferred embodiment of the present invention the step of positioning output optics includes employing side mounting blocks thereby to preserve precise mutual alignment of said at least one lens and said at least one waveguide, and the at least one waveguide includes a multiplicity of waveguides. The step of positioning the output optics includes positioning at least one lens so as to receive light from multiple ones of the multiplicity of waveguides.
Still further in accordance with a preferred embodiment of the present invention the lens is operative to couple light from a first number of fibers to an identical number of waveguides. Preferably the first number of waveguides comprises at least one waveguide.
Still further in accordance with a preferred embodiment of the present invention the at least one optical substrate is a light deflector.
Additionally in accordance with a preferred embodiment of the present invention, the optical device includes output optics receiving light from the at least one waveguide and including at least one output fiber.
Additionally or alternatively the output optics includes at least one lens fixed onto the base substrate by means of side mounting blocks thereby to preserve precise mutual alignment of the at least one lens and the at least one waveguide. The at least one optical substrate may be a light deflector and preferably the at least one optical substrate is formed of gallium arsenide.
Still further in accordance with a preferred embodiment of the present invention the at least one waveguide includes a multiplicity of waveguides and wherein the output optics includes at least one lens receiving light from multiple ones of the multiplicity of waveguides. Additionally or alternatively the output optics includes at least one lens receiving light from waveguides formed on multiple ones of the plurality of optical substrates. Furthermore the at least one optical substrate may be a light deflector.
The output optics may also include at least one lens fixed onto the base substrate by means of side mounting blocks thereby to preserve precise mutual alignment of the at least one lens and the at least one waveguide.
Additionally or preferably the at least one optical substrate is formed of gallium arsenide.
Still further in accordance with a preferred embodiment of the present invention the optical module includes at least one first substrate defining a multiplicity of optical fiber positioning grooves, a multiplicity of optical fibers fixed in each of the multiplicity of optical fiber positioning grooves on the at least one first substrate, whereby the multiplicity of optical fibers lie in an optical fiber plane. The ends of each of the multiplicity of optical fibers may lie substantially in a first predetermined arrangement in the optical fiber plane. A second substrate is preferably fixed on at least one first substrate such that an edge of the second substrate extends beyond the ends of each of the multiplicity of optical fibers, a lens assembly including a third substrate, and a lens fixed onto the third substrate, the lens assembly being mounted onto the second substrate such that the lens lies in a second predetermined arrangement with respect to the ends of each of the multiplicity of optical fibers. The separation between the lens and the ends of each of the multiplicity of optical fibers may be defined in a plane perpendicular to the optical fiber plane to a first degree of accuracy and the separation between the lens and the ends of each of the multiplicity of optical fibers may be defined in the optical fiber plane to a second degree of accuracy, less than the first degree of accuracy.
Further in accordance with a preferred embodiment of the present invention the lens includes a cylindrical lens.
Additionally in accordance with a preferred- embodiment of the present invention also including output optics receiving light from the at least one waveguide and including at least one output fiber. Additionally or alternatively the output optics includes at least one lens fixed onto the base substrate by means of side mounting blocks thereby to preserve precise mutual alignment of the at least one lens and the at least one waveguide. Preferably the at least one optical substrate is a light deflector and the at least one optical substrate is formed of gallium arsenide.
Further in accordance with a preferred embodiment of the present invention the at least one waveguide includes a multiplicity of waveguides and wherein the output optics includes at least one lens receiving light from multiple ones of the multiplicity of waveguides. Additionally or alternatively the multiplicity of waveguides is formed on a plurality of optical substrates and the output optics includes at least one lens receiving light from waveguides formed on multiple ones of the plurality of optical substrates.
Preferably the at least one optical substrate is a light deflector and the output optics includes at least one lens fixed onto the base substrate by means of side mounting blocks thereby to preserve precise mutual alignment of the at least one lens and the at least one waveguide. The at least one optical substrate may be formed of gallium arsenide.
There is also provided in accordance with a preferred embodiment of the present invention an optical device including at least one optical substrate having formed thereon at least one waveguide having a center which lies in a waveguide plane, a base substrate onto which the at least one optical substrate is fixed and defining at least one optical fiber positioning groove, and at least one optical fiber fixed in the at least one optical fiber positioning groove on the base substrate, whereby a center of the at least one optical fiber lies in a plane which is substantially coplanar with the waveguide plane.
Preferably electrical connections are mounted on the base substrate.
Additionally the at least one optical module is precisely positioned onto the base substrate and fixed thereto by means of side mounting blocks thereby to preserve precise mutual alignment of the at least one module and the at least one waveguide.
Additionally or alternatively the at least one optical substrate is a light deflector.
There is further provided in accordance with a preferred embodiment of the present invention a method for producing an optical device including the steps of forming at least one waveguide onto at least one optical substrate, mounting the at least one optical substrate onto at least one base substrate, and precisely positioning at least one optical module onto the base substrate, including employing side mounting blocks thereby to preserve precise mutual alignment of the at least one module and the at least one waveguide.
Additionally or alternatively the at least one optical module comprises a lens which is preferably a cylindrical lens.
Further in accordance with a preferred embodiment of the present invention the at least one optical module includes at least one optical fiber. Additionally or alternatively the at least one optical module also includes a lens which is operative to couple light from the at least one fiber to the at least one waveguide. Preferably the lens is operative to couple light from a first number of fibers to a greater number of waveguides.
Alternatively the lens is operative to couple light from a first number of fibers to an identical number of waveguides.
Additionally in accordance with a preferred embodiment of the present invention the first number of waveguides includes at least one waveguide.
Still further in accordance with a preferred the at least one optical substrate is a light deflector.
Additionally in accordance with a preferred embodiment of the present invention, the method for producing an optical device also includes the steps of providing output optics receiving light from the at least one waveguide and including at least one output fiber. Furthermore, the output optics may include at least one lens fixed onto the base substrate by means of side mounting blocks thereby to preserve precise mutual alignment of the at least one lens and the at least one waveguide. Additionally or alternatively the at least one optical substrate is a light deflector. Preferably the at least one optical substrate is formed of gallium arsenide.
Still further in accordance with a preferred embodiment of the present invention the at least one waveguide includes a multiplicity of waveguides and wherein the output optics includes at least one lens receiving light from multiple ones of the multiplicity of waveguides.
Further in accordance with a preferred embodiment of the present invention the at least one waveguide includes a multiplicity of waveguides formed on a plurality of optical substrates and wherein the output optics includes at least one lens receiving light from waveguides formed on multiple ones of the plurality of optical substrates. Additionally or alternatively the at least one optical substrate is a light deflector. Preferably the output optics includes at least one lens fixed onto the base substrate by means of side mounting blocks thereby to preserve precise mutual alignment of the at least one lens and the at least one waveguide. Preferably the at least one optical substrate is formed of gallium arsenide.
Still further in accordance with a preferred embodiment of the present invention the optical module includes at least one first substrate defining a multiplicity of optical fiber positioning grooves, a multiplicity of optical fibers fixed in each of the multiplicity of optical fiber positioning grooves on the at least one first substrate, whereby the multiplicity of optical fibers lie in an optical fiber plane and the ends of each of the multiplicity of optical fibers lie substantially in a first predetermined arrangement in the optical fiber plane, a second substrate fixed onto the at least one first substrate such that an edge of the second substrate extends beyond the ends of each of the multiplicity of optical fibers, a lens assembly including a third substrate, and a lens fixed onto the third substrate, the lens assembly being mounted onto the second substrate such that the lens lies in a second predetermined arrangement with respect to the ends of each of the multiplicity of optical fibers, whereby the separation between the lens and the ends of each of the multiplicity of optical fibers is defined in a plane perpendicular to the optical fiber plane to a first degree of accuracy and the separation between the lens and the ends of each of the multiplicity of optical fibers is defined in the optical fiber plane to a second degree of accuracy, less than the first degree of accuracy.
Additionally or alternatively the lens includes a cylindrical lens. Preferably the at least one optical substrate is a light deflector.
Additionally in accordance with a preferred embodiment of the present invention and also including providing output optics receiving light from said at least one waveguide and including at least one output fiber. Additionally or alternatively the output optics includes at least one lens fixed onto the base substrate by means of side mounting blocks thereby to preserve precise mutual alignment of the at least one lens and the at least one waveguide. The at least one optical substrate may be a light deflector and preferably the at least one optical substrate is formed of gallium arsenide.
Still further according to a preferred embodiment of the present invention the at least one waveguide includes a multiplicity of waveguides and wherein the output optics includes at least one lens receiving light from multiple ones of the multiplicity of waveguides.
Further in accordance with a preferred embodiment of the present invention the at least one waveguide includes a multiplicity of waveguides formed on a plurality of optical substrates and wherein the output optics includes at least one lens receiving light from waveguides formed on multiple ones of the plurality of optical substrates. Preferably the at least one optical substrate is a light deflector.
Additionally in accordance with a preferred embodiment of the present invention the output optics includes at least one lens fixed onto the base substrate by means of side mounting blocks thereby to preserve precise mutual alignment of the at least one lens and the at least one waveguide. Preferably the at least one optical substrate is formed of gallium arsenide.
There is also provided in accordance with yet another preferred embodiment of the present invention a method including forming on at least one optical substrate at least one waveguide having a center which lies in a waveguide plane, fixing the at least one optical substrate onto a base substrate and defining on the base substrate at least one optical fiber positioning groove, and fixing at least one optical fiber in the at least one optical fiber positioning groove on the base substrate, whereby a center of the at least one optical fiber lies in a plane which is substantially coplanar with the waveguide plane.
Preferably electrical connections are mounted on the base substrate.
Additionally the at least one optical module is precisely positioned onto the base substrate and fixed thereto by means of side mounting blocks thereby to preserve precise mutual alignment of the at least one module and the at least one waveguide.
Still further in accordance with a preferred embodiment of the present invention the at least one optical substrate is a light deflector. Preferably also including mounting electrical connections on said base substrate.
There is further provided in accordance with another preferred embodiment of the present invention a method for producing an optical device including the steps of lithographically forming a multiplicity of waveguides onto an optical substrate, mounting the optical substrate onto a base substrate, and precisely positioning a fiber optic module, having a multiplicity of optical fiber ends and an optical mode modifying lens, onto the base substrate, including using at least one external positioner, manipulating at least one of the fiber optic module and the base substrate relative to the other such that the mode of each optical fiber matches the mode of at least one corresponding waveguide with relatively low light loss, and fixing the fiber optic module in a desired relative position on the base substrate independently of the external positioner, and disengaging the at least one external positioner from the modulated light source.
Further in accordance with a preferred embodiment of the present invention the step of fixing includes employing side mounting blocks to fix the module in position on the base substrate upon precise mutual alignment of the module and the multiplicity of waveguides.
Still further in accordance with a preferred embodiment of the present invention also including the step of producing a fiber optic module which includes the steps of forming a multiplicity of optical fiber positioning grooves on at least one first substrate, placing each of a multiplicity of optical fibers in each of the multiplicity of optical fiber positioning grooves on the at least one first substrate, retaining each of the multiplicity of optical fibers in each of the multiplicity of optical fiber positioning grooves on the at least one first substrate, such that the multiplicity of optical fibers lie in an optical fiber plane, precisely defining the ends of each of the multiplicity of optical fibers so that they all lie substantially in a first predetermined arrangement, fixing a second substrate onto the first substrate such that an edge of the second substrate extends beyond the ends of each of the multiplicity of optical fibers, fixing a lens onto a third substrate, precisely aligning the third substrate in engagement with the edge of the second substrate such that the lens lies in a second predetermined arrangement with respect to the ends of each of the multiplicity of optical fibers, and fixing the third substrate in engagement with the edge of the second substrate such that the lens lies in a second predetermined arrangement with respect to the ends of each of the multiplicity of optical fibers, whereby the separation between the lens and the ends of each of the multiplicity of optical fibers is defined in a plane perpendicular to the optical fiber plane to a first degree of accuracy and the separation between the lens and the ends of each of the multiplicity of optical fibers is defined in the optical fiber plane to a second degree of accuracy, less than the first degree of accuracy.
Preferably the optical substrate is gallium arsenide and the optical device functions as a switch.